Australian scientists are building a ‘living seed bank’ to protect the last remaining fragments of rainforest from climate change. One goal is to avoid the extinction of ancient trees whose roots go back to Gondwana, the supercontinent that existed before Earth’s continents separated hundreds of millions of years ago.
Historically, Australia’s lush Big Scrub Rainforest flourished on an area of ​​185,000 acres (75,000 hectares) eastern Australia. However, human intervention and forest fires have reduced it to just 1% of its original area over the centuries. Now rising temperatures and drought threaten the remaining fragments.
These smaller areas contain fewer trees and shrinking diversity, making species vulnerable to changing weather, warming and disease.
This is of particular concern for species native to Gondwana, such as the Red Carabeen (Carrabina benthamiana) and the yellow carabeen (Sloanea woollsii) from lineages over 50 million years old, from when Australia was still attached to Antarctica, before Gondwana completely broke up.
These canopy trees can grow to heights of 115 and 164 feet (35 and 50 meters) and are “the master builders of the forest,” he said. Robert Kooymana plant biologist from Macquarie University in Australia who is involved in the research.
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In the new project called The Science of Saving Rainforestsrun by the Australian non-profit Big Scrub Rainforest Conservancy, scientists have selected 60 plant species, including several trees from the Gondwana era.
For each species, they collected DNA from leaf samples taken from dozens of plants across their geographic range to create the genome of each. Geographic distribution is important, Kooyman said: “What we get from this is a measure of how much diversity a species has in its genome, and how much of that diversity is structured in relation to climate change.”
This will reveal the genetics of rainforest plants that are able to thrive in warmer, drier environments that more closely resemble future climate conditions.
Using the genome, scientists can then identify and assemble populations of each plant species that will collectively contain as much of the diversity they uncover—including populations that are better equipped to withstand climate stress.
These candidate plants are currently being propagated and will be grown in a 37-acre (15 ha) research plantation in New South Wales, dubbed the “living seed bank”. In about five years, the raised trees will be ready to be planted in the remaining forest fragments.
The hope is to transform these sites into landscapes with a diversity reminiscent of a larger, untouched rainforest. And for species facing climate threats, the plantation offers a resource from which they can draw and “move material that increases their ability to deal with it,” Kooyman said. For trees from ancient lineages, such as the Carabeens originating from Gondwana, this could be an essential toolkit for survival.
“I admire the positive attitude and confidence of the people involved in plant genetics,” Sebastian Pfautsch, a researcher who has studied how trees respond to climate stress and is not involved in the research, told Live Science. However, he is cautious about her overall goal.
Pfautsch’s own research has revealed – through controlled experiments on eucalypt species – that the trees’ ability to adapt to higher temperatures may be limited. Pfautsch, who is a professor of urban planning and management at the University of Western Sydney, also expressed concern about the project’s reliance on public donations to keep it afloat: “Continued state and federal government funding is essential to ensure the trees grow.” he said. .
Kooyman remains optimistic, however, and believes the project could provide a blueprint for future genetic work—not just in rainforests, but in other endangered ecosystems around the world. “It’s a starting point to demonstrate what’s possible,” he said.